Example $1$

A geotechnical engineer is evaluating the stability of the slope. The

evaluation is considering the potential for a shear along the shear

surface shown. The soil has ${}^{\text{'}}=30$ and no cohesive strength.

Compute the shear

strength at point $A$

along this surface

when the groundwater

table is at level $B,$ the

compute the new

strength if it rose to

level $C.$ The unit

weight of the soil is

$120$ pcf above the

groundwater table and

$123$ pcf below.